Roberts B T, Ying C Y, Gautier J, Maller J L
Howard Hughes Medical Institute and Department of Pharmacology, University of Colorado Health Sciences Center, Box C-236, Denver, CO 80262, USA.
Proc Natl Acad Sci U S A. 1999 Mar 16;96(6):2800-4. doi: 10.1073/pnas.96.6.2800.
CDC7 is an essential gene required for DNA replication in Saccharomyces cerevisiae. Cdc7p homologs have recently been identified in vertebrates, but their role in DNA replication has not yet been addressed. Here we show that antibodies to the Xenopus laevis homolog, xCdc7, interfere with DNA replication in vivo in developing embryos and in vitro in cycling egg extracts. We also demonstrate cell cycle-dependent association of xCdc7 with the Mcm complex, which binds to replication origins and also is required for DNA synthesis. Taken together, these data indicate that the function of xCdc7 is conserved from fungi to vertebrates. xCdc7 protein accumulates after stimulation of resting oocytes with progesterone, suggesting a molecular explanation for previous observations that the development of the capacity for DNA replication requires protein synthesis late in meiosis I.
CDC7是酿酒酵母中DNA复制所必需的一个关键基因。最近在脊椎动物中鉴定出了Cdc7p的同源物，但它们在DNA复制中的作用尚未得到研究。在此我们表明，针对非洲爪蟾同源物xCdc7的抗体，在体内会干扰发育中胚胎的DNA复制，在体外会干扰循环卵提取物中的DNA复制。我们还证明了xCdc7与Mcm复合体存在细胞周期依赖性关联，Mcm复合体与复制起点结合，也是DNA合成所必需的。综合这些数据表明，xCdc7的功能从真菌到脊椎动物是保守的。在用孕酮刺激静止卵母细胞后，xCdc7蛋白会积累，这为之前的观察结果提供了一个分子解释，即DNA复制能力的发育在减数分裂I后期需要蛋白质合成。
